Currently the most commonly utilized fastener for necklaces and the like consists of a combination of two rings, the one ring being integral and being attached to one end of the necklace or chain, the other ring consisting of a tubular penannular portion defining a gap through which the integral ring can pass, the penannular portion housing a slidable latch portion which is spring biased in such a way that it closes the penannular portion under the urging of the spring. However, the latch portion can be pulled back to allow the integral ring to be passed into or out of engagement with the penannular portion. This conventional fastener works well enough, but is expensive to manufacture and is subject to sticking and breakage due to the moving parts.
A different approach to joining the ends of a garment accessory is illustrated in U.S. Pat. No. 1,840,896, Groh, and in U.S. Pat. No. 499,225, Hayes. Both of these fasteners are intended for use with a belt-like article in which, after connection together, the parts of the fastener are constantly tensioned together. However, the structure of these prior art fasteners, quite similar to each other, is not appropriate for use with a necklace or other loose article of adornment, in which the parts of the fastener are likely to be bounced around and are not under constant tension to keep them together.
The Groh and Hayes prior fasteners are constituted by a T-shaped male member and a female member with a slot through which the male member may be inserted, then rotated, then pulled into tension so that the members cannot be disengaged.
My earlier U.S. Pat. No. 4,502,192, issued Mar. 5, 1985 and entitled "Separable Fastener", utilizes the same basic structure as described above in connection with the Groh and Hayes prior fasteners, but adds an additional improved feature which prevents the parts of the fastener, once engaged, from being simply bounced or jiggled into disengagement. Specifically, my earlier patent provides a separable fastener including a male member having a stem portion and a T-shaped head portion with two arms projecting sidewards from the stem portion, and a female member constituted by an elongated body with a tail portion and a forward portion that is bent with respect to the tail portion. The elongated body of the female member has an opening adjacent the bent forward portion, which opening is of sufficient length to permit the insertion of one arm of the T-shaped head portion of the male member. However, the bent forward portion of the female member terminates at an edge which interferes with complete passage of the T-shaped head portion through the opening in any but one particular orientation of the male member with respect to the female member. That edge has an indentation adapted to receive the T-shaped head portion when it is in said one particular orientation, in order to avoid interference and permit complete passage of the T-shaped head portion through the opening. The opening further has a part wide enough to permit swivelling of the stem portion after passage of the T-shaped head portion through the opening.